Day-to-day variations in the F2 critical frequency

Abstract

From a comparison of ionospheric changes at F1 and F2 heights it is found that most of the variations in ƒoF2 can be attributed to variations in the incident ionizing radiation and in the rate of electron recombination. The ionizing radiation follows fairly closely the 2800 Mc/s solar radio flux. The recombination rate is affected by ionospheric storms and travelling disturbances, and it also shows a steady drift over the period studied.